zip64 compatibility problems

Martin Buchholz martinrb at
Wed Jan 16 03:40:30 UTC 2013

On Tue, Jan 15, 2013 at 6:24 PM, Xueming Shen <xueming.shen at> wrote:
> On 1/15/13 6:21 PM, Xueming Shen wrote:
>> zip3.0 has a flag to do the similar thing may be a compelling reason to
>> add such a system property, but make disabled default turns yourself
>> into the dark side:-)  have to explicitly turn the flag on will force the
>> people to think if this is something they really want to do.
>> Given it has been in the major releases for years, I don't think it's
>> possible to disable it in openjdk.
> I meant it's impossible to disable it by default..."

I agree with you that it's the right decision for OpenJDK proper.
You are consistent with zip 3.0 and also are obeying the zip spec  If one of the fields in the end of central directory
      record is too small to hold required data, the field should be
      set to -1 (0xFFFF or 0xFFFFFFFF) and the ZIP64 format record
      should be created.

It's a different story for the groups of users just now adopting jdk7.
The situation is a bit grim for those using jar files with >64k entries.
jdk7 is not only creating jar files that are unreadable by jdk6 - they
are also unreadable by the jdk7 launcher!  With no visible benefit for
the user!

So temporarily turning off zip64 seems a better choice for us.

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